Iāll start stating the obvious: 2-3 years cannot be considered ālong termā in the investment market. Not in the slightest.
There isnāt a fixed rule of what time frame constitutes a long term investment, but itās commonly considered to be between at least 5 years, and 10-20+ years.
2-3 years in the stock market, I would personally consider them a short (not even medium) term investment (and, although as I said thereās no fixed rule, Iām sure most people will agree).
Said that - yes, what youāre describing definitely is a risk.
The potential impact of it though depends on what other investments you hold in your portfolio.
I.e. if you currently had a portfolio made up for 80% of UK stocks in Ā£, adding a 5% of Americans stocks in USD wouldnāt be a problem.
On the other hand, if you currently had a portfolio of Ā£500 invested across UK stocks, dropping Ā£1,000 on US stocks in $ could maybe be a risk thatās too high for your own personal situation (as youād end up having 2/3 of your portfolio invested in a foreign currency).
Unfortunately thereās no answer applicable to everyone, everyone is different in this regard, it does genuinely depends on your personal risk level, on the āallowanceā that youāre giving yourself for investing, on the amount of cash savings you hold, on the amount of money that you would accept losing, etc.
Still, āwaiting for X to happenā has never been a good strategy in āinvestments theoryā.
Remember: time in the market beats timing the market.
a.k.a you never know when the USD will get weaker, so better to invest now an amount that you could afford to lose, rather than waiting for this or that.
Obviously, Iām not a financial advisor, and the above is just my strictly personal opinion.